1. Field of the Invention
The present invention relates to the pattern retrieving technology for retrieving a pattern from a search object, and more specifically to the pattern retrieving technology for collectively and simultaneously processing retrieval requests when the retrieval requests are received from a plurality of terminal devices, and returning retrieval results to respective terminal devices, thereby exceedingly shortening the entire processing time.
2. Description of the Related Art
Conventionally, a full text retrieval system has been adopted using a character string collating method. A full text retrieval system using a character string collating method refers to a system of checking whether or not there is a specified character string in the text data to be searched while sequentially collating the specified character string with text data to be searched from the start to the end of the text data to be searched.
However, in the full text retrieval system using the character string collating method, the CPU of the system performs a collating operation while the CPU of the system is scanning the text data. Therefore, any other processes cannot be performed during the collating operation, and it is difficult for a system, in which a plurality of user terminals are connected to a retrieval device, to provide a retrieving service to the plurality of user terminals.
That is, when a plurality of user terminals are connected to a retrieval device which performs a full text searching process, and each of the user terminals frequently issues a retrieval request to the device, the CPU of the retrieval device which has started a retrieving process cannot perform other processes during the text scanning operation, and all other requests are kept waiting until the CPU has completed the character collating operation.
Furthermore, there has been the problem that, when retrieval device receives the same retrieval requests from different user terminals at almost the same time, it has to wastefully repeat the same retrieving process for the retrieval requests.